The subject matter of the present invention relates to a new method for safely packaging shaped charges for transportation by common carrier.
If a box of commercial oil-well shaped charges must be transported by common airline carrier, the box of shaped charges must be certified "class C" by a competent authority, such as the Department of Transportion. In accordance with one of the certification requirements, if a shaped charge in a shipping box should accidentally detonate, the jet produced therefrom must not propagate outside of the shipping box. This is normally accomplished by packaging the charges in a pairwise fashion, as shown in FIG. 1, so that the jet from the detonated shaped charge is destroyed by the induced detonation and subsequent liner collapse of the opposing shaped charge. It is important that the shaped charges be arranged as in FIG. 1 and not as in FIG. 2, since otherwise the first shaped charge would merely detonate the second shaped charge and cause propagation of a second jet. The problem with the arrangement shown in FIG. 1, however, is that some shaped charge designs produce jets which are sufficiently long, fast, and coherent enough to penetrate the adjacent mirror-imaged shaped charge, thus potentially exiting the shipping box; that is, the jet may be powerful enough so that some of it will pass through the destructive influence of the explosive detonation and through the collapse of the adjacent shaped charge. If this happens, the jet may endanger structures or persons present within the immediate vicinity of the shipping box. A severe safety hazard is created.